By Ranjith Nambiar Roll no.41 SEMINAR ON ANTIMATTER By Ranjith Nambiar Roll no.41

INTRODUCTION Antimatter is real. Energy density of chemical reaction is 1×10 J/kg. nuclear fission is 8×10 J/kg. nuclear fusion is 3×10 J/kg. matter antimatter reaction is 9×1016 J/kg. Highest energy release per unit mass. Complete conversion of mass into energy. ×

WHAT IS MATTER? Everything around us. Basic components: electrons. protons. neutrons.

WHAT IS ANTIMATTER? Opposite of normal matter. Basic components are: positrons. antiprotons. antineutrons.

HISTORY OF ANTIMATTER. In 1928,Paul A.M.Dirac revised Einstein’s famous equation E=mc². Dirac’s equation E=±mc². Positrons discovered by Carl Anderson in 1932. Antiprotons discovered in 1955. Antiatoms discovered in 1995 by CERN.

PRODUCTION OF ANTIMATTER. Created from energy. Protons are smashed into target. Matter-antimatter particles are spontaneously created. Antiproton head towards the Antiproton Decelerator.

ANTIPROTON DECCELERATOR (AD) It consists of vacuum tubes. vacuum pumps. magnets. radiofrequency cavities. high voltage instruments. electronic circuits.

WORKING OF AD. Antiproton have energy spread. transverse oscillations. Focusing magnets. Radiofrequency cavities decelerate the antiproton.

AD EXPERIMENTS. ASACUSA (Atomic Spectroscopy And Collision Using Slow Antiprotons). ATHENA (Antihydrogen Production and Precision Experiments). ATRAP (Cold Anti hydrogen for precise laser Spectroscopy).

STORAGE. Traps. Appropriate configuration of electric and magnetic fields. Good vacuum.

ANTIMATTER IN PROPULSION SYSTEM Annihilation. Newtonian rocket. 100 milligram for Space Shuttle.

ANTIMATTER PROPULSION SYSTEMS. Two choice of propulsion 1)Electron-positron annihilation. produces high energy gamma rays. impossible to control. very dangerous. 2)Proton-antiproton annihilation. produces charged particles. mass left over after annihilation.

1)SOLID CORE. Solid core heat exchanger. Superheats hydrogen propellants. Specific impulse:1000sec

2)GAS CORE. Annihilation occurs in hydrogen propellant. Particles controlled in magnetic field. Loss in the form of gamma rays. Specific impulse:2500sec

3)PLASMA CORE. Annihilation of larger amount of antimatter. Loss in the form of gamma rays. Plasma is expelled to produce thrust. Specific impulse between 5000 to 10000sec.

4)BEAM CORE. Direct one to one annihilation. Used directly as the exhausted propellant. Specific impulse:10,000,000sec

POSITRON EMISSION TOMOGRAPHY (PET) SCAN. Positron incorporated in a special fluid injected into the patient. Annihilate with electrons. Energy emerges as gamma rays. PET radiograph reveals inner structure. Widely used in brain scans.

ANTIMATTER DETONATION. Output highly depends on regular matter surrounding the bomb. Gamma rays are absorbed. Lose half their energy per 500 to 1000m of air compared to 20cm of concrete. Explosion would not cause much physical damage. No practical or destructive as conventional nuclear weapons.

ANTIMATTER IN NATURE. Matter & antimatter were created in gigantic Big Bang. Two possibilities: Either antimatter completely disappeared. Separated from each other.

ALPHA MAGNETIC SPECTROMETER High energy particle detector. Carried on Space Shuttle. In 2004,a new version of experiment installed on the International Space Station.

PROBLEMS IN PRODUCTION. Only 1 to 10 nano grams produced a year. Most expensive substance on earth. 1 gram cost about $62.5 trillion. So not economical using current technology.

PROBLEMS IN STORAGE. Current trap can only store 1010 antiproton for one week. Next stage an improvement to 1012 antiproton storage. For complete antimatter propulsion, 1020 antiprotons needed to be stored.

CONCLUSION Due to the highest energy release per unit mass of any known reaction we can say that antimatter will be a future fuel but need a reliable method of producing large amount of it.

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